Located between the Neotropical biogeographical region, the biosphere reserve is situated in the ‘Sierra de Cucharas’, a mountainous chain derived from the large Sierra Madre Chain. It is one of the most ecologically rich and diverse places of Mexico. It comprises 14 vegetation types, dominated by the tropical sclerophyllous forest. The conservation of the ecosystems of El Cielo is essential: they host a number of threatened plants and animal species as the oso negro (Ursus americanus), jaguaroundi (Herpailurus yagouaroundi), tigrillo (Leopardus wiedii), jaguar (Pantera onca), ocelote (Leopardus pardalis), and cabeza de viejo (Eira barbara). The local population of 6,208 inhabitants (1999), dispersed in 47 communities, are mainly engaged in seasonal agriculture as maize, beans, pumpkin and fruits crops, hunting and forestry exploitation. Local communities lack minimal public services as potable water, electricity and good health conditions. Programmes on ecotourism development, environmental education and biotic monitoring and as well as research on ethnobotany have taken place. The biosphere reserve’s principal goal is to implement integral projects on social development and environmental research under the reserve’s administration council. The reserve receives 1,000 national and 300 international visitors every year (1999).